Most modern engines are equipped with overhead camshafts for improved fuel economy and increased power. Commonly, the crankshaft of the engine will drive the camshaft through a chain interconnecting a gear on the crankshaft and a gear on the camshaft. It is common to have one or more guides to guide the chain and at least one tensioner.
One way to improve the fuel economy of an engine is to reduce the friction of the moving components and also to reduce the mass and inertia of the moving parts. However, this reduction in friction cane come with an increase in torsionals of both the camshaft and crankshaft. These torsionals can cause the free strand of the chain between the crank and tensioner arm system to vibrate and flap as it enters the tension arm or guide. This flapping can cause excessive wear on the face of the tension arm system in contact with the chain. This face is generally formed of plastic.
What is needed is a chain tensioner apparatus that will eliminate these concerns and reduce wear on the apparatus components.
The present invention is directed to an apparatus for applying a continuous tension to a chain. The apparatus includes a tensioner arm having a distal end. A face is secured to the tensioner arm and has a portion that extends beyond the distal end of the tensioner arm. A blade spring is secured to the tensioner arm and also has a portion extending beyond the distal end. The blade spring urges the face into contact with a chain. A hydraulic tensioner urges the tensioner arm against the chain.